I'm trying to build a non MPI code and get this error: Undefined symbols: "_ompi_mpi_comm_self", referenced from: _ompi_mpi_comm_self$non_lazy_ptr in libamrelliptic2d.Darwin.g++-4.gfortran.DEBUG.OPT.PETSC.a(PetscLinearSolver.o) (maybe you meant: _ompi_mpi_comm_self$non_lazy_ptr) In the past I have linked libmpiuni.a but that did not seem to get created. Did libmpiuni.a go away or did my make fail ... Mark